Model/Engine size: 640d Coupe M Sport
Fuel economy combined: 51.4 mpg
Green-Car-Guide rating: 9/10
The 155 mph BMW 640d Coupe may not sound like a green car, but it can achieve 51.4 mpg with emissions of 145 g/km CO2 , therefore in terms of fuel economy, it’s a class-leader for grand tourers.
As with virtually all modern BMWs, it’s the complete range of statistics that impresses the most. In addition to the figures above, the 640d Coupe achieves 0-62 mph in 5.5 seconds, it has a power output of 313 hp, but perhaps most significant is the huge 630 Nm of torque.
Compared to the previous 635d, the new 640d Coupe has 27 more hp, 50 Nm more torque, its 0-62 mph time is 0.8 seconds faster, it’s 10.5 mpg more economical, and it has 39 g/km lower CO2 emissions.
This impressive set of statistics is largely due to BMW’s EfficientDynamics technologies, which are standard across the 6 Series range. One particular feature that makes a significant difference in terms of emissions is the Auto StartStop feature on the eight speed automatic transmission.
All models also have technology such as Brake Energy Regeneration, Electric Power Steering (EPS), the needbased operation of ancillary components, and active air flaps behind the grille.
Here’s an interesting question: what do you think the petrol/diesel UK sales split is for the 6 Series Coupe? Maybe 80% petrol, 20% diesel? Well, you may surprised to learn that in 2010, 93% of sales were diesel, with petrol sales representing just 7%. If you’d have predicted ten years earlier that more than 90% of the sales of such a grand tourer would have been with a diesel engine, people would have thought you were crazy.
So against opposition such as the petrol-only Jaguar XK, how does the diesel 6 Series stack up? Well, the 640d has one key strong point – its engine. The 3-litre straight-six diesel has twin turbos and we’ve already seen that it has massive torque. It doesn’t take long to realise that although it’s normally hushed, it can also make a great noise. Its two turbos, one small, one large, work in a sequential way, to provide almost continual high levels of torque from low revs.
Power is fed through an eight-speed automatic gearbox. You can change manually using the paddle shifters behind the steering wheel, but it’s likely that the vast majority of people would just leave it in Drive. The gearbox does a good job of translating the diesel engine into a smooth driving experience, although in manual mode it still seems keen to override the driver’s choices.
The 640d is a grand tourer rather than a sports car, and the engine is well suited to such a role. This 6 Series shows that the days of noisy diesel engines intruding into the interior environment are well gone; at 70 mph it feels like you’re doing 30 mph.
If you do need to accelerate past dawdling traffic then the car can certainly pick up its heels, in a way that is very unlike diesel engines from a few years ago. Today the torque from engines such as this straight six makes the 640d feel like it has more grunt than most petrol engines.
The 640d is of course rear-wheel drive, with excellent handling, good levels of grip, and yet also a comfortable ride. The 6 Series is a large car, and you’re very aware of its width on narrow Welsh mountain roads – but it feels more agile than it should do for its size.
BMW has worked to improve the chassis on this new model, and it comes with various settings controlling the driving experience. Drive Dynamic Control (DDC) comes as standard, which allows drivers to choose how responsive they want the gearbox, steering and throttle.
The first of these DDC settings is the new ECO PRO mode. This ensures that the car is set up to deliver the best possible fuel consumption by adjusting the engine management system, accelerator mapping and gearshift characteristics to favour a relaxed, low revving driving style. At the same time, power usage for electronically-operated functions such as climate control is regulated. To achieve this efficiency, the response from the accelerator pedal becomes muted. However the result is that by driving in this mode through mountain roads we achieved 40 mpg.
There are then the Comfort + and Comfort settings. These do what they say on the tin and offer the sort of driving experience that most people would want from such a car.
Then there is Sport mode, which provides greater levels of responsiveness for a ‘press-on’ driving style, and Sport +, which disengages a proportion of the traction control systems.
This range of settings really should provide something for everyone’s driving requirements, from comfortable to sporty.
BMW’s Adaptive Drive system is also available as an option, which features electrically controlled dampers and antiroll stabilisation.
There’s also an optional Integral Active Steering system, which combines Active Steering for the front axle with a steering rear axle, allowing the steering angle and power assistance to be controlled at both the front and the rear with the help of electric motors.
Inside the car, the cockpit feels luxurious but very familiar to anyone who has experienced the new 5 Series – this is good from the point of view of quality and efficiency, but it could still benefit from feeling a little more special to provide some extra differentiation between the 5 and the 6 Series.
Being a 2+2, the 6 Series has two seats in the rear, and they offer more legroom than most other 2+2s, but they’re certainly not ideal for full-grown adults.
The exterior looks like an enlarged 3 Series Coupe from the side, and a wider and lower 3 Series Coupe from the rear. This is all good. It’s just the front where you feel more creativity could have been applied, particularly in the area of the headlights. The 5 Series is a good-looking car; the flat-bottomed headlights on the 6 Series look as though they should have a bit more character.
The Coupe has a good-sized (460-litre) boot, and of course its primary design goal is to accommodate golf bags – it can swallow three of them.
The 6 Series comes with levels of equipment that you would expect in a car of this class. The 640d Coupe comes as standard with 18 inch alloy wheels and leather upholstery, as well as a new sat nav system complete with a wide 10.2-inch screen. The new Real Time Traffic Information (RTTI) system is an enhanced BMW ConnectedDrive feature, and it collates information (anonymously) from other drivers’ mobile phones to find out where the traffic jams are, and if required it will re-route you on a faster road. Road networks can be divided into distances as short as 500m and the information is automatically updated every 3 minutes.
Our test car had M Sport kit, which accounts for 97% of sales, and this includes a body kit, 19-inch alloy wheels, Sport seats and M Sport multifunction leather rimmed steering wheel. The M Sport spec costs £66,745, and our car had £8,650 worth of options, such as adaptive drive at £3400, adaptive LED headlamps at £1665, and a head-up display at £980. That comes to a grand total of £75,395.
The 640d SE Coupe, representing just 3% of sales, costs £62,080.
There’s also two turbo petrol engines available, the 640i and the 650i. These achieve 36.2 and 26.6 mpg, and 181 and 246 g/km CO2 respectively.
The new Coupe, equating to 63% of purchases, is on sale now. The remaining 37% of 6 Series sales are accounted for by the convertible.
The BMW 640d Coupe is a truly accomplished grand tourer. It’s very quiet and refined under most conditions, but if you do want to drive progressively, it has an appealing engine note, and rewarding rear-wheel drive handling. The engine does everything that you would want of it, with the exception of providing the edgy driving sensation of a petrol supercar. However such a trait isn’t something that the character of the 6 Series would benefit from, and the advantage of the diesel unit is the promise of 51.4 mpg, a level of economy that no petrol supercar or grand tourer could hope to come close to. The twin turbo diesel offers impressive levels of urge due to its huge torque, and its responses are all that most people will need in such a grand tourer.
The front of the car could be more appealing, particularly the headlights, and more could be done in the interior to distance it further from the 5 Series. But that is pretty much the full extent of our complaints, and compared to the big picture of a 155 mph grand tourer with 630 Nm torque being able to achieve over 50 mpg, these are relatively trivial gripes, therefore the BMW 640d Coupe gets a Green-Car-Guide rating of 9 out of 10. It’s a sign of the times that buyers of this car are likely to appreciate the car’s light thirst for fuel, along with the much-reduced need to have to stop at fuel stations to fill up.
Fuel economy extra urban: TBC
Fuel economy urban: TBC
CO 2 emissions: 145 g/km
Green rating: VED band F – first year £130
Company car tax liability (2011/12): 21% (640d SE)
Insurance group: TBC
Power: 313 bhp
Max speed: 155 mph
0-62mph: 5.5 seconds
See other BMW road tests:
BMW 640d Coupe review, BMW 640d Coupe road test